UK policeman admits lying in 'plebgate' scandal

LONDON—A British policeman admitted lying about witnessing a senior politician insult police officers and pleaded guilty on Friday to misconduct in public office.

Keith Wallis claimed that he saw Conservative Party politician Andrew Mitchell swearing at and insulting police, a hotly disputed incident which raised questions about the integrity of Britain's largest police force.

Mitchell was forced to resign as Conservative chief whip soon after the altercation, which took place in September 2012 outside the prime minister's office. Mitchell admitted losing his temper and swearing at police when they refused to let him cycle through the Downing Street gate, but denied claims that he called officers "plebs"—a derogatory term for working-class people.

A heated dispute then erupted over whether Mitchell or police were telling the truth, and investigations followed.

The dispute continues. Toby Rowland, a police officer involved in the altercation, maintains that Mitchell called him a "pleb," and is suing the politician for libel.

Wallis, 53, was arrested in December after it emerged that he sent an email to a lawmaker falsely claiming to have seen Mitchell shouting obscenities at police. Detectives found that Wallis was not present at the scene.

On Friday, Wallis admitted lying and offered to resign. He will be sentenced later. Wallis four other officers also are facing misconduct hearings.